Methods: data analysis; Planets and satellites: detection; Planets and satellites: gaseous planets; Planets and satellites: individual: TOI-5678; Exo-planets; Gas giant; Methods. Data analysis; Neptune; Planet and satellite: gaseous planet; Planet and satellite: individual: TOI-5678; Planets and satellites; Planets and satellites: detections; Planets and satellites: individual; Radial velocity; Astronomy and Astrophysics; Space and Planetary Science; astro-ph.EP
Abstract :
[en] Context. A large sample of long-period giant planets has been discovered thanks to long-term radial velocity surveys, but only a few dozen of these planets have a precise radius measurement. Transiting gas giants are crucial targets for the study of atmospheric composition across a wide range of equilibrium temperatures and, more importantly, for shedding light on the formation and evolution of planetary systems. Indeed, compared to hot Jupiters, the atmospheric properties and orbital parameters of cooler gas giants are unaltered by intense stellar irradiation and tidal effects. Aims. We aim to identify long-period planets in the Transiting Exoplanet Survey Satellite (TESS) data as single or duo-transit events. Our goal is to solve the orbital periods of TESS duo-transit candidates with the use of additional space-based photometric observations and to collect follow-up spectroscopic observations in order to confirm the planetary nature and measure the mass of the candidates. Methods. We use the CHaracterising ExOPlanet Satellite (CHEOPS) to observe the highest-probability period aliases in order to discard or confirm a transit event at a given period. Once a period is confirmed, we jointly model the TESS and CHEOPS light curves along with the radial velocity datasets to measure the orbital parameters of the system and obtain precise mass and radius measurements. Results. We report the discovery of a long-period transiting Neptune-mass planet orbiting the G7-type star TOI-5678. Our spectroscopic analysis shows that TOI-5678 is a star with a solar metallicity. The TESS light curve of TOI-5678 presents two transit events separated by almost two years. In addition, CHEOPS observed the target as part of its Guaranteed Time Observation program. After four non-detections corresponding to possible periods, CHEOPS detected a transit event matching a unique period alias. Follow-up radial velocity observations were carried out with the ground-based high-resolution spectrographs CORALIE and HARPS. Joint modeling reveals that TOI-5678 hosts a 47.73 day period planet, and we measure an orbital eccentricity consistent with zero at 2σ. The planet TOI-5678 b has a mass of 20 ± 4 Earth masses (M) and a radius of 4.91 ± 0.08 R Using interior structure modeling, we find that TOI-5678 b is composed of a low-mass core surrounded by a large H/He layer with a mass of 3.2±1.7-1.3 M. Conclusions. TOI-5678 b is part of a growing sample of well-characterized transiting gas giants receiving moderate amounts of stellar insolation (11 S). Precise density measurement gives us insight into their interior composition, and the objects orbiting bright stars are suitable targets to study the atmospheric composition of cooler gas giants.
Disciplines :
Space science, astronomy & astrophysics
Author, co-author :
Ulmer-Moll, S. ; Observatoire Astronomique de l'Université de Genève, Versoix, Switzerland ; Physikalisches Institut, University of Bern, Bern, Switzerland
Osborn, H.P. ; Physikalisches Institut, University of Bern, Bern, Switzerland ; Department of Physics and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, United States
Tuson, A. ; Astrophysics Group, Cavendish Laboratory, University of Cambridge, Cambridge, United Kingdom
Egger, J.A. ; Physikalisches Institut, University of Bern, Bern, Switzerland
Lendl, M. ; Observatoire Astronomique de l'Université de Genève, Versoix, Switzerland
Maxted, P. ; Astrophysics Group, Keele University, Staffordshire, United Kingdom
Bekkelien, A.; Observatoire Astronomique de l'Université de Genève, Versoix, Switzerland
Simon, A.E. ; Physikalisches Institut, University of Bern, Bern, Switzerland
Olofsson, G. ; Department of Astronomy, Stockholm University, AlbaNova University Center, Stockholm, Sweden
Adibekyan, V. ; Instituto de Astrofísica e Ciências Do Espaço, Universidade Do Porto, Caup, Porto, Portugal
Alibert, Y. ; Physikalisches Institut, University of Bern, Bern, Switzerland
Bonfanti, A. ; Space Research Institute, Austrian Academy of Sciences, Graz, Austria
Bouchy, F.; Observatoire Astronomique de l'Université de Genève, Versoix, Switzerland
Brandeker, A. ; Department of Astronomy, Stockholm University, AlbaNova University Center, Stockholm, Sweden
Fridlund, M. ; Leiden Observatory, University of Leiden, Leiden, Netherlands ; Department of Space, Earth and Environment, Chalmers University of Technology, Onsala Space Observatory, Onsala, Sweden
Gandolfi, D. ; Dipartimento di Fisica, Universita Degli Studi di Torino, Torino, Italy
Mordasini, C.; Physikalisches Institut, University of Bern, Bern, Switzerland
Persson, C.M. ; Department of Space, Earth and Environment, Chalmers University of Technology, Onsala Space Observatory, Onsala, Sweden
Salmon, S. ; Observatoire Astronomique de l'Université de Genève, Versoix, Switzerland
Serrano, L.M. ; Dipartimento di Fisica, Universita Degli Studi di Torino, Torino, Italy
Sousa, S.G. ; Instituto de Astrofísica e Ciências Do Espaço, Universidade Do Porto, Caup, Porto, Portugal
Wilson, T.G. ; Centre for Exoplanet Science, Supa School of Physics and Astronomy, University of St Andrews, St Andrews, United Kingdom
Rieder, M.; Physikalisches Institut, University of Bern, Bern, Switzerland
Hasiba, J.; Space Research Institute, Austrian Academy of Sciences, Graz, Austria
Asquier, J.; Estec, European Space Agency, Noordwijk, Netherlands
Sicilia, D. ; Inaf - Osservatorio Astrofisico di Catania, Catania, Italy
Walter, I. ; German Aerospace Center (DLR), Institute of Optical Sensor Systems, Berlin, Germany
Alonso, R. ; Instituto de Astrofisica de Canarias, La Laguna, Spain ; Departamento de Astrofisica, Universidad de la Laguna, La Laguna, Spain
Anglada, G. ; Institut de Ciencies de l'Espai (ICE, CSIC), Bellaterra, Spain ; Institut d'Estudis Espacials de Catalunya (IEEC), Barcelona, Spain
Barrado Y Navascues, D. ; Depto. de Astrofisica, Centro de Astrobiologia (CSIC-INTA), Madrid, Spain
Barros, S.C.C. ; Instituto de Astrofísica e Ciências Do Espaço, Universidade Do Porto, Caup, Porto, Portugal ; Departamento de Física e Astronomia, Faculdade de Ciências, Universidade Do Porto, Porto, Portugal
Baumjohann, W. ; Space Research Institute, Austrian Academy of Sciences, Graz, Austria
Beck, M. ; Observatoire Astronomique de l'Université de Genève, Versoix, Switzerland
Beck, T.; Physikalisches Institut, University of Bern, Bern, Switzerland
Benz, W. ; Physikalisches Institut, University of Bern, Bern, Switzerland ; Center for Space and Habitability, University of Bern, Bern, Switzerland
Billot, N. ; Observatoire Astronomique de l'Université de Genève, Versoix, Switzerland
Bonfils, X. ; Université Grenoble Alpes, Cnrs, Ipag, Grenoble, France
Borsato, L. ; Inaf, Osservatorio Astronomico di Padova, Padova, Italy
Broeg, C. ; Physikalisches Institut, University of Bern, Bern, Switzerland ; Center for Space and Habitability, University of Bern, Bern, Switzerland
Bárczy, T. ; Admatis, Miskolc, Hungary
Cabrera, J.; Institute of Planetary Research, German Aerospace Center (DLR), Berlin, Germany
Charnoz, S. ; Université de Paris, Institut de Physique du Globe de Paris, Cnrs, Paris, France
Cointepas, M.; Observatoire Astronomique de l'Université de Genève, Versoix, Switzerland ; Université Grenoble Alpes, Cnrs, Ipag, Grenoble, France
Cameron, A. Collier ; Centre for Exoplanet Science, Supa School of Physics and Astronomy, University of St Andrews, St Andrews, United Kingdom
Csizmadia, Sz. ; Institute of Planetary Research, German Aerospace Center (DLR), Berlin, Germany
Cubillos, P.E.; Space Research Institute, Austrian Academy of Sciences, Graz, Austria ; Inaf - Osservatorio Astrofisico di Torino, Pino Torinese, Italy
Davies, M.B. ; Centre for Mathematical Sciences, Lund University, Lund, Sweden
Deleuil, M. ; Aix-Marseille Univ, Cnrs, Cnes, Lam, Marseille, France
Deline, A.; Observatoire Astronomique de l'Université de Genève, Versoix, Switzerland
Delrez, Laetitia ; Université de Liège - ULiège > Département d'astrophysique, géophysique et océanographie (AGO) > Exoplanets in Transit: Identification and Characterization
Demangeon, O.D.S. ; Instituto de Astrofísica e Ciências Do Espaço, Universidade Do Porto, Caup, Porto, Portugal ; Departamento de Física e Astronomia, Faculdade de Ciências, Universidade Do Porto, Porto, Portugal
Demory, B.-O. ; Center for Space and Habitability, University of Bern, Bern, Switzerland
Dumusque, X.; Observatoire Astronomique de l'Université de Genève, Versoix, Switzerland
Ehrenreich, D. ; Observatoire Astronomique de l'Université de Genève, Versoix, Switzerland ; Centre Vie dans l'Univers, Faculté des Sciences, Université de Genève, Genève 4, Switzerland
Eisner, N.L.; Center for Computational Astrophysics, Flatiron Institute, New York, United States
Erikson, A.; Institute of Planetary Research, German Aerospace Center (DLR), Berlin, Germany
Fortier, A. ; Physikalisches Institut, University of Bern, Bern, Switzerland ; Center for Space and Habitability, University of Bern, Bern, Switzerland
Fossati, L. ; Space Research Institute, Austrian Academy of Sciences, Graz, Austria
Gillon, Michaël ; Université de Liège - ULiège > Département d'astrophysique, géophysique et océanographie (AGO)
Grieves, N. ; Observatoire Astronomique de l'Université de Genève, Versoix, Switzerland
Güdel, M.; University of Vienna, Department of Astrophysics, Vienna, Austria
Hagelberg, J. ; Observatoire Astronomique de l'Université de Genève, Versoix, Switzerland
Helled, R.; Institute for Computational Science, University of Zurich, Zurich, Switzerland
Hoyer, S. ; Aix-Marseille Univ, Cnrs, Cnes, Lam, Marseille, France
Isaak, K.G. ; Science and Operations Department - Science Division (SCI-SC), Directorate of Science, European Space Agency (ESA), European Space Research and Technology Centre (ESTEC), Noordwijk, Netherlands
Kiss, L.L.; Konkoly Observatory, Research Centre for Astronomy and Earth Sciences, Budapest, Hungary ; Elte Eötvös Loránd University, Institute of Physics, Budapest, Hungary
Laskar, J. ; Imcce, UMR8028 Cnrs, Observatoire de Paris, Psl Univ., Sorbonne Univ., Paris, France
Des Etangs, A. Lecavelier ; Institut d'Astrophysique de Paris, UMR7095 Cnrs, Université Pierre & Marie Curie, Paris, France
Lovis, C. ; Observatoire Astronomique de l'Université de Genève, Versoix, Switzerland
Magrin, D. ; Inaf, Osservatorio Astronomico di Padova, Padova, Italy
Nascimbeni, V. ; Inaf, Osservatorio Astronomico di Padova, Padova, Italy
Otegi, J.; Observatoire Astronomique de l'Université de Genève, Versoix, Switzerland
Ottensammer, R.; Department of Astrophysics, University of Vienna, Vienna, Austria
Pagano, I. ; Inaf - Osservatorio Astrofisico di Catania, Catania, Italy
Pallé, E. ; Instituto de Astrofisica de Canarias, La Laguna, Spain
Peter, G. ; Institute of Optical Sensor Systems, German Aerospace Center (DLR), Berlin, Germany
Piotto, G. ; Inaf, Osservatorio Astronomico di Padova, Padova, Italy ; Dipartimento di Fisica e Astronomia Galileo Galileia, Università Degli Studi di Padova, Padova, Italy
Pollacco, D.; Department of Physics, University of Warwick, Coventry, United Kingdom
Psaridi, A.; Observatoire Astronomique de l'Université de Genève, Versoix, Switzerland
Queloz, D. ; Eth Zurich, Department of Physics, Zurich, Switzerland ; Cavendish Laboratory, Cambridge, United Kingdom
Ragazzoni, R. ; Inaf, Osservatorio Astronomico di Padova, Padova, Italy ; Dipartimento di Fisica e Astronomia Galileo Galileia, Università Degli Studi di Padova, Padova, Italy
Rando, N.; Estec, European Space Agency, Noordwijk, Netherlands
Rauer, H. ; Institute of Planetary Research, German Aerospace Center (DLR), Berlin, Germany ; Zentrum für Astronomie und Astrophysik, Technische Universität Berlin, Berlin, Germany
Ribas, I. ; Institut de Ciencies de l'Espai (ICE, CSIC), Bellaterra, Spain ; Institut d'Estudis Espacials de Catalunya (IEEC), Barcelona, Spain
Santos, N.C. ; Instituto de Astrofísica e Ciências Do Espaço, Universidade Do Porto, Caup, Porto, Portugal ; Departamento de Física e Astronomia, Faculdade de Ciências, Universidade Do Porto, Porto, Portugal
Scandariato, G. ; Inaf - Osservatorio Astrofisico di Catania, Catania, Italy
Smith, A.M.S. ; Institute of Planetary Research, German Aerospace Center (DLR), Berlin, Germany
Steller, M. ; Space Research Institute, Austrian Academy of Sciences, Graz, Austria
Szabó, G.M.; Elte Eötvös Loránd University, Gothard Astrophysical Observatory, Szombathely, Hungary ; MTA-ELTE Exoplanet Research Group, Szombathely, Hungary
Ségransan, D. ; Observatoire Astronomique de l'Université de Genève, Versoix, Switzerland
Thomas, N.; Physikalisches Institut, University of Bern, Bern, Switzerland
Udry, S. ; Observatoire Astronomique de l'Université de Genève, Versoix, Switzerland
Van Grootel, Valérie ; Université de Liège - ULiège > Département d'astrophysique, géophysique et océanographie (AGO) > Astrophysique stellaire théorique et astérosismologie
Venturini, J.; Observatoire Astronomique de l'Université de Genève, Versoix, Switzerland
Walton, N.A. ; Institute of Astronomy, University of Cambridge, Cambridge, United Kingdom
This work has been carried out within the framework of the National Centre of Competence in Research PlanetS supported by the Swiss National Science Foundation under grants 51NF40_182901 and 51NF40_205606. The authors acknowledge the financial support of the SNSF. A.T. acknowledges support from an STFC PhD studentship. M.L. acknowledges support of the Swiss National Science Foundation under grant number PCEFP2194576. P.M. acknowledges support from STFC research grant number ST/M001040/1. J.E., Y.A., and M.J.H. acknowledge the support of the Swiss National Fund under grant 200020_172746. A.Br. was supported by the SNSA. M.F. and C.M.P. gratefully acknowledge the support of the Swedish National Space Agency (DNR 65/19, 174/18, 177/19). D.G. and L.M.S. gratefully acknowledge financial support from the CRT foundation under Grant No. 2018.2323 “Gaseous or rocky? Unveiling the nature of small worlds”. C.M. acknowledges the support from the SNSF under grant 200021_204847 “PlanetsInTime”. S.G.S. acknowledges support from FCT through FCT contract nr. CEECIND/00826/2018 and POPH/FSE (EC). A.C.C. and T.W. acknowledge support from STFC consolidated grant numbers ST/R000824/1 and ST/V000861/1, and UKSA grant number ST/R003203/1. We acknowledge support from the Spanish Ministry of Science and Innovation and the European Regional Development Fund through grants ESP2016-80435-C2-1-R, ESP2016-80435-C2-2-R, PGC2018-098153-B-C33, PGC2018-098153-B-C31, ESP2017-87676-C5-1-R, MDM-2017-0737 Unidad de Excelencia Maria de Maeztu-Centro de Astrobiología (INTA-CSIC), as well as the support of the Generalitat de Catalunya/CERCA programme. The MOC activities have been supported by the ESA contract No. 4000124370. S.C.C.B. acknowledges support from FCT through FCT contracts nr. IF/01312/2014/CP1215/CT0004. X.B., S.C., D.G., M.F. and J.L. acknowledge their role as ESA-appointed CHEOPS science team members. This project was supported by the CNES. The Belgian participation to CHEOPS has been supported by the Belgian Federal Science Policy Office (BELSPO) in the framework of the PRODEX Program, and by the University of Liège through an ARC grant for Concerted Research Actions financed by the Wallonia-Brussels Federation; L.D. is an F.R.S.-FNRS Postdoctoral Researcher. This work was supported by FCT - Fundaçâo para a Ciência e a Tecnologia through national funds and by FEDER through COMPETE2020 – Programa Operacional Competitividade e Internacionalizacâo by these grants: UID/FIS/04434/2019, UIDB/04434/2020, UIDP/04434/2020, PTDC/FIS-AST/32113/2017 & POCI-01-0145-FEDER- 032113, PTDC/FIS-AST/28953/2017 & POCI-01-0145-FEDER-028953, PTDC/FIS-AST/28987/2017 & POCI-01-0145-FEDER-028987, O.D.S.D. is supported in the form of work contract (DL 57/2016/CP1364/CT0004) funded by national funds through FCT. This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement SCORE No 851555). J.H. supported by the Swiss National Science Foundation (SNSF) through the Ambizione grant #PZ00P2_180098. P.E.C. is funded by the Austrian Science Fund (FWF) Erwin Schroedinger Fellowship, program J4595-N. B.-O.D. acknowledges support from the Swiss State Secretariat for Education, Research and Innovation (SERI) under contract number MB22.00046 and from the Swiss National Science Foundation (PP00P2-190080). This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (project FOUR ACES; grant agreement No 724427). It has also been carried out in the frame of the National Centre for Competence in Research PlanetS supported by the Swiss National Science Foundation (SNSF). D.E. acknowledges financial support from the Swiss National Science Foundation for project 200021_200726. M.G. and V.V.G. are F.R.S.-FNRS Senior Research Associates. S.H. gratefully acknowledges CNES funding through the grant 837319. This work was granted access to the HPC resources of MesoPSL financed by the Region Ile de France and the project Equip@Meso (reference ANR-10-EQPX-29-01) of the programme Investissements d’Avenir supervised by the Agence Nationale pour la Recherche. L.Bo., G.Br., V.Na., I.Pa., G.Pi., R.Ra., G.Sc.,V.Si., and T.Zi. acknowledge support from CHEOPS ASI-INAF agreement n. 2019-29-HH.0. This work was also partially supported by a grant from the Simons Foundation (PI: Queloz, grant number 327127). I.R.I. acknowledges support from the Spanish Ministry of Science and Innovation and the European Regional Development Fund through grant PGC2018-098153-B- C33, as well as the support of the Generalitat de Catalunya/CERCA programme. Gy.M.Sz. acknowledges the support of the Hungarian National Research, Development and Innovation Office (NKFIH) grant K-125015, a a PRODEX Experiment Agreement No. 4000137122, the Lendület LP2018-7/2021 grant of the Hungarian Academy of Science and the support of the city of Szombathely. N.A.W. acknowledges UKSA grant ST/R004838/1. K.G.I. is the ESA CHEOPS Project Scientist and is responsible for the ESA CHEOPS Guest Observers Programme. She does not participate in, or contribute to, the definition of the Guaranteed Time Programme of the CHEOPS mission through which observations described in this paper have been taken, nor to any aspect of target selection for the programme. The authors acknowledge the use of public TESS data from pipelines at the TESS Science Office and at the TESS Science Processing Operations Centre.
Adibekyan, V. Z., Sousa, S. G., Santos, N. C., et al. 2012, A&A, 545, A32
Adibekyan, V., Figueira, P., Santos, N. C., et al. 2015, A&A, 583, A94
Adibekyan, V., Dorn, C., Sousa, S. G., et al. 2021, Science, 374, 330
Albrecht, S. H., Dawson, R. I., & Winn, J. N. 2022, PASP, 134, 1038
Aller, A., Lillo-Box, J., Jones, D., Miranda, L. F., & Barceló Forteza, S. 2020, A&A, 635, A128
Atreya, S. K., Hofstadter, M. H., In, J. H., et al. 2020, Space Sci. Rev., 216, 18
Banfield, D., & Murray, N. 1992, Icarus, 99, 390
Barros, S. C. C., Akinsanmi, B., Boué, G., et al. 2022, A&A, 657, A52
Bashi, D., Helled, R., Zucker, S., & Mordasini, C. 2017, A&A, 604, A83
Batalha, N. E., Mandell, A., Pontoppidan, K., et al. 2017, PASP, 129, 064501
Benz, W., Broeg, C., Fortier, A., et al. 2021, Exp. Astron., 51, 109
Blackwell, D. E., & Shallis, M. J. 1977, MNRAS, 180, 177
Bonfanti, A., Ortolani, S., Piotto, G., & Nascimbeni, V. 2015, A&A, 575, A18
Bonfanti, A., Ortolani, S., & Nascimbeni, V. 2016, A&A, 585, A5
Bonfanti, A., Delrez, L., Hooton, M. J., et al. 2021, A&A, 646, A157
Bonomo, A. S., Desidera, S., Benatti, S., et al. 2016, Celest. Mech. Dyn. Astron., 126, 145
Borucki, W. J., Koch, D., Basri, G., et al. 2010, Science, 327, 977
Bruntt, H., Bedding, T. R., Quirion, P. O., et al. 2010, MNRAS, 405, 1907
Castelli, F., & Kurucz, R. L. 2003, A&A, 210, A20
Cubillos, P. E., & Blecic, J. 2021, MNRAS, 505, 2675
Dalba, P. A., Gupta, A. F., Rodriguez, J. E., et al. 2020, AJ, 159, 241
Dalba, P. A., Kane, S. R., Isaacson, H., et al. 2021, AJ, 161, 103
Dalba, P. A., Kane, S. R., Dragomir, D., et al. 2022, AJ, 163, 61
Deline, A., Queloz, D., Chazelas, B., et al. 2020, A&A, 635, A22
Delrez, L., Ehrenreich, D., Alibert, Y., et al. 2021, Nat. Astron., 5, 775
Dorn, C., Venturini, J., Khan, A., et al. 2017, A&A, 597, A37
Doyle, A. P., Davies, G. R., Smalley, B., Chaplin, W. J., & Elsworth, Y. 2014, MNRAS, 444, 3592
Dransfield, G., Triaud, A. H. M. J., Guillot, T., et al. 2022, MNRAS, 515, 1328
Dubber, S. C., Mortier, A., Rice, K., et al. 2019, MNRAS, 490, 5103
Emsenhuber, A., Mordasini, C., Burn, R., et al. 2021 a, A&A, 656, A69
Emsenhuber, A., Mordasini, C., Burn, R., et al. 2021 b, A&A, 656, A70
Emsenhuber, A., Mordasini, C., & Burn, R. 2023, Planetary Population Synthesis and the Emergence of Four Classes of Planetary System Architectures (Berlin: Springer)
Espinoza, N., & Jordán, A. 2015, MNRAS, 450, 1879
Espinoza, N., Kossakowski, D., & Brahm, R. 2019, MNRAS, 490, 2262
Faria, J. P., Santos, N. C., Figueira, P., & Brewer, B. J. 2018, J. Open Source Softw., 3, 487
Feroz, F., Balan, S. T., & Hobson, M. P. 2011, MNRAS, 415, 3462
Foreman-Mackey, D., Morton, T. D., Hogg, D. W., Agol, E., & Schölkopf, B. 2016, AJ, 152, 206
Fridlund, C. V. M. 2008, Phys. Scrip. Vol. T, 130, 014009
Fridlund, M., Livingston, J., Gandolfi, D., et al. 2020, MNRAS, 498, 4503
Fulton, B. J., Petigura, E. A., Blunt, S., & Sinukoff, E. 2018, PASP, 130, 044504
Fulton, B. J., Rosenthal, L. J., Hirsch, L. A., et al. 2021, ApJS, 255, 14
Gaia Collaboration (Brown, A. G. A., et al.) 2021, A&A, 649, A1
Garai, Z., Osborn, P., Gandolfi, D., et al. 2023, A&A, 674, A44
Gill, S., Bayliss, D., Cooke, B. F., et al. 2020 a, MNRAS, 491, 1548
Gill, S., Wheatley, P. J., Cooke, B. F., et al. 2020 b, ApJ, 898, L11
Gray, D. F. 2008, The Observation and Analysis of Stellar Photospheres (Cambridge: Cambridge University Press)
Gustafsson, B., Edvardsson, B., Eriksson, K., et al. 2008, A&A, 486, 951
Hakim, K., Rivoldini, A., Van Hoolst, T., et al. 2018, Icarus, 313, 61
